Question

What is the difference between allosteric inhibition and noncompetitive inhibition ? ​

Answer 1

Answer:

Explanation:

A noncompetitive inhibitor inhibits the action of an enzyme by binding to the enzyme somewhere other than the active site.

An allosteric inhibitor binds to the enzyme, inducing it to assume an inactive form.

All noncompetitive inhibition is allosteric inhibition, but not all allosteric inhibition is noncompetitive inhibition because certain forms of allosteric inhibition can prevent the substrate from binding to the active site. It can thus either be noncompetitive or competitive.

Answer 2

Allosteric Inhibition

• Allosteric enzymes display a sigmoidal curve in contrast to the hyperbolic curve displayed by Michaelis-Menten Enzymes. This is because most allosteric enzymes contain multiple sub-units which can affect each other when the substrate binds to the enzyme.
• Allosteric enzymes have two states: a low affinity state dubbed the “T” state and the high affinity “R” state. Inhibitors work by preferentially binding to the T state of an allosteric enzyme, causing the enzyme to maintain this low affinity state.

Non-Competitive Inhibitors

• Non-competitive inhibitors bind to another location on the enzyme and as such decrease VMAX. However, KM is unchanged. This is demonstrated by a lower maximum on a graph plotting enzyme activity against substrate concentration and a higher y-intercept on a Lineweaver-Burke plot when compared with no inhibitor.